[Insight-users] Some questions in understanding the N4ITK

[Wenwu]

Hi everyone,

There are some problems when I learn the N4ITK. Firstly, in the
paper-"N4ITK:Nick's N3 ITK Implementation For MRI Bias Field Correction" ,
I found there are 9 parameters (m_MaskMabel, m_numberOfHistogamBins,
m_WeinerFilterNoise, m_BiasFieldFullWitdthAtHalfMaximum... ,)need to set,
it can also be found in the N4ITK package.  However, in the lastest ITK4.0,
in the project-ITKBiasCorrectionTestDriver, I open the CMakeLists.txt, and
some code is as followiing:

itk_add_test(NAME itkN4BiasFieldCorrectionImageFilterTest1
      COMMAND ITKBiasCorrectionTestDriver
      --compare DATA{Baseline/N4ControlPoints_3D.nii.gz}
               ${ITK_TEST_OUTPUT_DIR}/N4ControlPoints_3D.nii.gz
    itkN4BiasFieldCorrectionImageFilterTest
    2
    DATA{${ITK_DATA_ROOT}/Input/HeadMRVolumeCompressed.mha}            #
input
    ${ITK_TEST_OUTPUT_DIR}//N4ControlPoints_3D.nii.gz
# *control
point lattice  .* , I also can not understand the mean of this parameter

    3
# shrink factor
    10x10x10                                                           #
number of iterations
    none                                                               #
mask
    150                                                                #
spline distance
    )